Question:
Mark $(\sqrt{)}$ against the correct answer in each of the following:
The direction cosines of the vector $\overrightarrow{\mathrm{a}}=(-2 \hat{\mathrm{i}}+\hat{\mathrm{j}}-5 \hat{\mathrm{k}})$ are
A. $-2,1,-5$
B. $\frac{1}{3}, \frac{-1}{6}, \frac{-5}{6}$
C. $\frac{2}{\sqrt{30}}, \frac{1}{\sqrt{30}}, \frac{5}{\sqrt{30}}$
D. $\frac{-2}{\sqrt{30}}, \frac{1}{\sqrt{30}}, \frac{-5}{\sqrt{30}}$
Solution:
